An attempt has been made to provide secure storage on a removable medium, such as an optical disk. However, the attempt to provide the secure storage had several limitations, such as, for example: the removable medium was not fully backward compatible with earlier versions of the medium; a firmware implementation was very complex due to, for example, a logical block address (LBA) space with “holes” as well as other issues; edge cases, and a changing maximum number of available tracks or sessions on the medium.
Physical sectors are all sectors on a medium, including those sectors not normally accessible by a user. LBA space includes only those sectors on the medium that the user can read and typically starts at some physical sector number other than zero.